Static Electricity
Electric Charge
OBJECTIVES
 Students will learn about positive
and negative charges
 Students will conduct experiments
and observe the results
 Students will learn how friction can
cause a transfer of electrons
MATERIALS
Experiment #1: balloons, piece of cloth
CORE LEARNING GOALS
3.2.1 The student will make informed
decisions and predictions based upon the
results of simulations and data from
research.
CALCULATOR SKILLS
Experiment #2: balloons, thread, wool
cloth
Experiment #3: empty toilet paper roll,
plastic ruler, wool cloth
EQUATIONS
Experiment #4
 2 tin cans
 3 sheets of paraffin wax
 thread
 paper clip
 sewing needle
 balloons
 piece of wool
 fluorescent bulb
 heat source such as a Bunsen burner
Challenge #1: fluorescent bulb, balloons
ACTIVITIES
1. Hands-On Activities
Experiment #1
Experiment #2
Experiment #3
Experiment #4
Challenge #1
2. Discussion
3. Think, Pair, Share
ADDITIONAL RESOURCES
Document: Electricity Vocabulary lists terms and definitions.
http://www.sciencemadesimple.com/static.html
http://amasci.com/emotor/stmiscon.html
Static Electricity
Electric Charge
TEACHER GUIDE
Lesson/Background:
Matter is made up of particles having positive charges and negative charges. The
negative particles are called electrons. Matter is neutrally charged when there are just as
many positive charges as negative charges. Neutral matter can become charged by
removing or adding electrons. All of the following experiments can be explained in
terms of matter being charged and the interaction it had when coming in contact with
other neutral or charged matter. Many objects can be charged by rubbing them with
another substance. When the different materials touch, one material tends to hold onto
electrons more tightly and “steals” electrons from the other surface as they touch. That
surface is then negatively charged because it has more electrons than protons and the
other surface is positively charged. When the surfaces separate, the regions of opposite
charge also separate. Rubbing a balloon with wool causes electrons to leave the wool and
move onto the balloon that makes the balloon negative. Even though the balloon has
both positive and negative charges, the overall charge is negative. This would mean that
the resulting charge on the wool would be positive since electrons were removed from the
originally neutral wool.
Hands On Activities:
Experiment #1
Blow up and tie off a number of balloons. Prepare some of them by running them against
a sweater or article of clothing. Do not charge the others. Have students come to the
board and try to stick them in a horizontal row. Obviously some will stick to the board
and others will not. Solicit reasons from the class, and once someone suggests that you
must rub the balloon first before attempting to stick it to the board ask what kind of
material it needs to be rubbed against.
Teacher Tip:
Wool, cotton and hair are the most common substances a balloon should be rubbed
against because they give up electrons more readily.
During the discussion some balloons will probably fall. Ask students for an explanation
to this behavior.
Teacher Tip:
Over a period of time electrons will transfer from the balloon to the board and the
induced positive charge on the board will be neutralized resulting in the balloon falling
down.
Teacher Tip:
This experiment is demonstrated in the movie: staticElectricityExp1.mpg
Experiment #2:
Blow up four identical balloons and tie a thread to each. Hold two balloons together by
the two threads and show that the balloons will hang down against each other. Take the
same two balloons and rub them with a wool cloth. Ask students to predict what will
happen when they are brought side by side.
Teacher Tip:
They will repel each other so that they cannot touch. Both balloons were charged by
friction.
Take two other balloons and rub one with wool. Ask students to predict what will
happen.
Teacher Tip:
They will attract each other, one is charged by friction and the other by induction.
Teacher Tip:
This experiment is demonstrated in the movie: staticElectricityExp2.mpg
Experiment #3
On a flat table, place a hollow cardboard toilet paper roll. Take a plastic ruler and rub it
vigorously with the piece of wool for 30 seconds. Approach the roll slowly with the ruler
until the roll begins to move. Then move the ruler away from the roll in the same
direction that the roll started to move. In other words it will be like the ruler is pulling
the roll across the table. It is important that the roll be perfectly round or the roll may not
“chase” the ruler.
Teacher Tip:
The ruler has been charged negatively by friction and as it approaches the roll it induces a
positive charge on the leading edge of the roll. This in turn is attracted to the ruler. As
long as ruler and the roll do not touch, the ruler can pull the roll along.
Teacher Tip:
This experiment is demonstrated in the movie staticElectricityExp3.mpg
Experiment #4
For this exercise you will need two tall tin cans, three pieces of paraffin wax, thread, a
paper clip, a rubber balloon, and wool cloth. Set each can on one of the blocks of
paraffin and place the third block on the open ends of the two cans. Unbend the paper
clip part of the way. Use the heat source to heat the unbent end of the paper clip. Then
use the heated paper clip to make a small hole in the center of the top piece of wax. You
may have to repeat the heating process a couple of times before you get all the way
through the wax. Suspend the needle from the block with a thread in such a way that the
paper clip hangs down in between the two cans.
Rub the balloon with the wool cloth and bring it close to one of the cans. Observe.
Teacher Tip:
The needle will move back and forth between the cans. It you may have to recharge the
balloon a couple of times to build enough charge in the can to make the needle move.
Try moving the cans as close as one inch apart if the needle will not move. Also make
sure the needle is light enough.
The negatively charged balloon when brought close to one of the cans repelled the
electrons to the other side of the can (the side closer to the paper clip). The neutral
charged paper clip is then attracted to this charged can and moves to make contact with it.
In making contact the clip receives electrons making it the same charge as the can and
then moves away since like charges repel. The paper clip, now negatively charged,
induces a positive charge in the second can and is attracted to it. Upon making contact it
gives up its charge to the second can and is attracted again to the first. The back and
forth motion is repeated a number of times. It is very important that the paraffin be used.
It serves as an insulating agent so that electrons are not drained off too readily. If enough
charge is built up, the needle may stick to one can for an extended period of time.
Teacher Tip:
This experiment is demonstrated in the movie staticElectricityExp4.mpg
Challenge #1
(a) Hold up the fluorescent bulb and ask students how you can get it to glow without
putting it into a lamp or socket. Have students discuss what they know about static
electricity.
(b) Make the room as dark as possible. Invite a student to rub the balloon against his/her
head.
(c) While you are holding the bulb, have the student touch the balloon to the metal
contact at one end of the bulb. Observe and record what happens in your science journal.
Discuss what happened and why. How could you make the bulb glow longer and
brighter?
Teacher Tip:
The bulb could glow longer and brighter if the charge between the balloon and the
fluorescent tube became stronger. Fluorescent tubes are filled with a gas that gets
“excited” when even a small amount of electricity is apllied to it. When you touch the
end of the tube with the balloon, electrons jump from the balloon to the metal conducting
tip of the bulb. These electrons hit low pressure mercury gas in the bulb. When the gas
molecules become excited, they give off ultraviolet rays. These rays excite the phosporus
coating on the inner surface of the glass tube that gives off white light.
Discussion:
1. What makes plastic wrap such as Saran Wrap stick to food storage containers? Is it
due to static electricity?
Electric charges on the plastic wrap attract the sides of bowls causing it to cling. The
charge was probably put on the plastic wrap when it was pulled off the roll quickly.
2. What causes clothes in a clothes dryer to get all mixed up and stick together when you
take them out of the dryer?
By the clothes tumbling over and over and coming in contact with each other there is a
lot of transfer of electrons due to friction. When the dryer stops different parts of the
clothing have opposite charges and tend to cling to each other.
3. A good research project would be to have students find out how anti-static-cling
products that we put in our dryer work.
The fabric softener coats the fibers of the clothes. This prevents the fibers from rubbing
together and transferring electrons due to friction.
4. Picture the following. A boy and a girl are on opposite sides of the front seat of the
car. After awhile he scoots across the plastic seat cover towards the center. She also
scoots toward the middle. Still more time goes by, he scoots, she scoots. Slowly their
lips are approaching each other, and SNAP, CRACKLE, POP they undergo an electric
experience. What happened?
As they scooted across the plastic seat cover they both were being charged due to friction.
When their lips made contact there was a sudden discharge creating the electric
experience.
Think, Pair, Share:
Question: Why is there more static electricity in the winter?
Answer: There is less humidity in the winter. When it is humid, the water in the air
helps to move the electrons away from a charged object more quickly.
Static Electricity
Electric Charge
Student Worksheet
Experiment #1
Blow up and tie off a number of balloons. Prepare some of them by running them against
a sweater or article of clothing. Do not charge the others. Have students come to the
board and try to stick them in a horizontal row. Obviously some will stick to the board
and others will not. Solicit reasons from the class, and once someone suggests that you
must rub the balloon first before attempting to stick it to the board ask what kind of
material it needs to be rubbed against.
During the discussion some balloons will probably fall. Ask students for an explanation
to this behavior.
Experiment #2:
Blow up four identical balloons and tie a thread to each. Hold two balloons together by
the two threads and show that the balloons will hang down against each other. Take the
same two balloons and rub them with a wool cloth. Predict what will happen when they
are brought side by side.
Take two other balloons and rub one with wool. Predict what will happen.
Experiment #3
On a flat table, place a hollow cardboard toilet paper roll. Take a plastic ruler and rub it
vigorously with the piece of wool for 30 seconds. Approach the roll slowly with the ruler
until the roll begins to move. Then move the ruler away from the roll in the same
direction that the roll started to move. In other words it will be like the ruler is pulling
the roll across the table. It is important that the roll be perfectly round or the roll may not
“chase” the ruler.
Experiment #4
For this exercise you will need two tall tin cans, three pieces of paraffin wax, thread, a
paper clip, a rubber balloon, and wool cloth. Set each can on one of the blocks of
paraffin and place the third block on the open ends of the two cans. Unbend the paper
clip part of the way. Use the heat source to heat the unbent end of the paper clip. Then
use the heated paper clip to make a small hole in the center of the top piece of wax. You
may have to repeat the heating process a couple of times before you get all the way
through the wax. Suspend the needle from the block with a thread in such a way that the
paper clip hangs down in between the two cans.
Rub the balloon with the wool cloth and bring it close to one of the cans. Observe.
Challenge #1
(a) Hold up the fluorescent bulb and ask students how you can get it to glow without
putting it into a lamp or socket. Have students discuss what they know about static
electricity.
(b) Make the room as dark as possible. Invite a student to rub the balloon against his/her
head.
(c) While you are holding the bulb, have the student touch the balloon to the metal
contact at one end of the bulb. Observe and record what happens in your science journal.
Discuss what happened and why. How could you make the bulb glow longer and
brighter?
Discussion Questions
1. What makes plastic wrap such as Saran Wrap stick to food storage containers? Is it
due to static electricity?
2. What causes clothes in a clothes dryer to get all mixed up and stick together when you
take them out of the dryer?
3. A good research project would be to have students find out how anti-static-cling
products that we put in our dryer work.
4. Picture the following. A boy and a girl are on opposite sides of the front seat of the
car. After awhile he scoots across the plastic seat cover towards the center. She also
scoots toward the middle. Still more time goes by, he scoots, she scoots. Slowly their
lips are approaching each other, and SNAP, CRACKLE, POP they undergo an electric
experience. What happened?
Think, Pair, Share
Question: Why is there more static electricity in the winter?